Japanese healthcare company Daiichi Sankyo Co Ltd (TYO:4568) and British-Swedish biopharmaceutical company AstraZeneca plc (STO:AZN) (LON:AZN) (Nasdaq:AZN) announced on Tuesday that the US Food and Drug Administration (FDA) has accepted and granted Priority Review to a supplemental Biologics License Application for DATROWAY as a first-line treatment for adults with unresectable or metastatic triple negative breast cancer who are not candidates for PD-1 or PD-L1 inhibitor therapy.

The FDA action date under the Prescription Drug User Fee Act is 2 June 2026.

The application is supported by results from the phase 3 TROPION-Breast02 trial, in which DATROWAY demonstrated a statistically significant 5.0-month improvement in median overall survival versus chemotherapy and a 43% reduction in the risk of disease progression or death. The treatment also showed higher and more durable response rates than chemotherapy, with an objective response rate of 62.5% and median duration of response of 12.3 months.

Its safety profile was consistent with prior studies, with grade 3 or higher treatment-related adverse events occurring in 33% of DATROWAY patients versus 29% with chemotherapy, including one grade 5 interstitial lung disease event adjudicated as drug-related.

DATROWAY is a TROP2-directed antibody drug conjugate discovered by Daiichi Sankyo and jointly developed and commercialised with AstraZeneca. The filing is being reviewed under the FDA's Project Orbis framework.